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Abstract:

A copper alloy material for electric/electronic components according to
the present invention is characterized in that a average grain size of 1
to 50 μm that is designated by ((a+b)/2) in which a thickness of a
grain is defined to be (a) and a width thereof is defined to be (b) which
is on a cross section that is vertical to a rolling direction, an aspect
ratio (a/b) thereof is between 0.5 and 1.0, an aspect ratio (a/b) of a
grain before performing a bend working and an aspect ratio (a'/b') of
which a grain is effected by a tensile stress after performing a bend
working of 90 degrees satisfy the following (Formula 1) of:
2≦(a+b)/(a'/b')≦15 (Formula 1),
and the copper alloy material has a bending workability to be excellent.

Claims:

1.-5. (canceled)

6. A copper alloy material for electric/electronic components,wherein a
average grain size of 1 to 50 μm that is designated by ((a+b)/2) in
which a thickness of a grain is defined to be (a) and a width thereof is
defined to be (b) which is on a cross section that is vertical to a
rolling direction,an aspect ratio (a/b) thereof is between 0.5 and 1.0,an
aspect ratio (a/b) of a grain before performing a bend working and an
aspect ratio (a'/b') of which a grain is effected by a tensile stress
after performing a bend working of 90 degrees satisfy a following
(Formula 1):2.ltoreq.(a+b)/(a'/b')≦15 (Formula 1),andsaid copper
alloy material has a bending workability to be excellent.

7. The copper alloy material for electric/electronic components according
to claim 6,wherein a Vickers hardness (Hv) on a cross section is between
180 and 350, which is vertical to said rolling direction before
performing said bend working, andsaid copper alloy material has a bending
workability to be excellent.

8. The copper alloy material for electric/electronic components according
to claim 6, comprising:Ni and/or Co between 1.0 mass % and 4.5 mass %,
respectively;Si between 0.2 mass % and 1.2 mass %; anda remaining portion
which is formed of Cu and an unavoidable impurity.

9. The copper alloy material for electric/electronic components according
to claim 7, comprising:Ni and/or Co between 1.0 mass % and 4.5 mass %,
respectively;Si between 0.2 mass % and 1.2 mass %; anda remaining portion
which is formed of Cu and an unavoidable impurity.

10. The copper alloy material for electric/electronic components according
to claim 8,wherein said copper alloy material further comprises at least
one nature between 0.005 mass % and 1.0 mass %, which is selected from a
group that is comprised of Sn, Zn, Cr and Mg.

11. The copper alloy material for electric/electronic components according
to claim 9,wherein said copper alloy material further comprises at least
one nature between 0.005 mass % and 1.0 mass %, which is selected from a
group that is comprised of Sn, Zn, Cr and Mg.

12. The copper alloy material for electric/electronic components according
to claim 6,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

13. The copper alloy material for electric/electronic components according
to claim 7,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

14. The copper alloy material for electric/electronic components according
to claim 8,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

15. The copper alloy material for electric/electronic components according
to claim 9,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

16. The copper alloy material for electric/electronic components according
to claim 10,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

17. The copper alloy material for electric/electronic components according
to claim 11,wherein it becomes able to perform a solution annealed
recrystallization heat treatment with a temperature between 700.degree.
C. and 1000.degree. C. before performing a final rolling, andit becomes
able to perform a quick cooling with a cooling rate of faster than or
equal to 100.degree. C. per second.

Description:

TECHNICAL FIELD

[0001]The present invention relates to a copper alloy material which is to
be applied to electric/electronic components.

BACKGROUND ART

[0002]Conventionally, as a material for such as a connector and a terminal
for a usage of an electric apparatus and of an electronic equipment, for
a relay, for a switch, or the like, a copper alloy (such as a phosphor
bronze or a brass, or the like) is made use as widely, which is superior
in electrical conduction property and in thermal conduction property.

[0003]However, with being accompanied by a packaging in size to be smaller
and by being lightened of the electrical apparatus and of the electronic
equipment, a part and component which is to be mounted thereon becomes to
be mounted in high density. And hence various kinds of properties are
required as well for a copper alloy material that is to be made use for
these. For example, for the copper alloy to be made use a material
becomes to be made use which has a thickness to be thinner with being
accompanied by the packaging in size to be smaller and by being lightened
of the part and component. And then the thinner a material is, the
stronger a strength (the higher a hardness) for the material becomes to
be required in order to obtain a contact pressure load which is similar
to the conventional. In the meantime however, in a case where the
strength of a general metallic material becomes to be improved an
elongation becomes to be decreased and also a bending workability becomes
to be deteriorated, that are heretofore known. Moreover, regarding this
bending workability a matter is required of which a material should be
bended with having a bend radius to be further smaller (a further severe
bend working), that is accompanied by the packaging in size to be smaller
of the electric/electronic components.

[0004]Further, in order to satisfy the properties of the strength and the
bending workability that are conflicted to each other it is regarded that
in a case where a method for improving the strength by making use of a
precipitation hardening is applied to a copper alloy among a variety of
method for hardening, such as a solution heat hardening, a work
hardening, the precipitation hardening, or the like, it becomes difficult
for the bending workability to be deteriorated. And then among those an
alloy that is called a Corson alloy has an ability for hardening to be
higher as extremely among a plurality of alloys of a precipitation type,
for which Ni and Si are added into Cu and a precipitate is to be formed
which is comprised of the Ni and the Si and then the same is to be
hardened. And hence the same is made use for some alloys on the market,
such as the CDA70250 which is the registered alloy of Copper Development
Association (CDA) or the like.

[0005]And then there are many examples that are heretofore known in which
there are described regarding such as the strength, a grain size, the
bending workability, or the like of this Corson alloy.

[0006]For example, there is disclosed the specification of the grain size
in the following patent document 1. In the meantime however, there is not
disclosed any specification regarding a size of the precipitates and a
space of those. Moreover, there is not disclosed any description at all
regarding a variation of a grain after performing a bend working.

[0007]And in the meantime, an objective of the patent document 2 is
regarding a stress relaxation resistance. Moreover, a compression of a
grain size of a final product is specified, in the meantime however,
there is not disclosed any description at all regarding a variation of a
grain size after performing a bend working. And in the meantime, an
application of the patent document 3 is to a lead frame, in the meantime
however, there is not clarified at all regarding such as a lower limit of
a grain size or a lower limit of a size of a precipitate or the like.
Moreover, there is not disclosed any description at all regarding a
variation of a grain size before and after performing a bend working.

[0008]And in the meantime, in accordance with the following patent
document 4 there are disclosed the descriptions regarding the average
grain size and the bending workability, in the meantime however, there is
not disclosed any description at all regarding a specification of a
distortion of a grain nor of a precipitate after performing a bend
working. And in the meantime, in accordance with the patent document 5
there is disclosed the description of a stamping property regarding the
average grain size, in the meantime however, there is not disclosed any
description at all regarding a bending workability.

[0009]And in the meantime, in accordance with the patent document 6 there
is disclosed the description regarding the grain size, in the meantime
however, there is not disclosed any description at all regarding a size
of a precipitate nor a bending workability. And in the meantime, in
accordance with the patent document 7 there is disclosed the description
of containing phosphorus (P) with a variety of the indispensable elements
and of the grain size, in the meantime however, there is not disclosed
any description at all regarding a bending workability.

[0010]And in the meantime, in accordance with the following patent
document 8 and the patent document 9 there is disclosed the description
regarding the grain size, in the meantime however, there is not disclosed
any description at all regarding a size of a precipitate nor a bending
workability. And in the meantime, in accordance with the patent document
10 there is disclosed the description regarding the relation between the
grain size and the inclusion after performing the final rolling, in the
meantime however, there is not disclosed any description at all regarding
a matter after performing a bend working.

[0011]And thus not only in accordance with these heretofore known patent
documents but there cannot be found any heretofore known examples in
which a variation in shape of a grain size before and after performing a
bend working is examined in detail. And then in accordance with the
examples therein there is disclosed the description regarding the matter
having good and bad points of the strength, of the grain size and of the
bending workability as simply. In the meantime however, there cannot be
found any documents at all in which a distortion action (an aspect ratio)
of a grain size is paid attention.

[0012]Here, the bend working is specified in the JIS-Z2248: 2006 of
Japanese Industrial Standards: "Metallic materials--Bend test". Moreover,
a test method of a (W) bending with a bend angle of 90 degrees is
described as well in the JBMA-T307 (1999) in accordance with the
technical standards of Copper Elongation Society of Japan: "Standard test
method of bend formability for sheets and strips of copper and copper
alloys". And then the evaluation of these is performed in general.
Further, good and bad points of this bending workability are judged by
performing an evaluation whether or not occurring any crack by performing
an observation of a top part of a test piece which is bended with a
variety of bend radiuses.

[0013]For example, in a case where the (W) bending is performed with the
bending angle of 90 degrees stresses of two different types become to be
occurred that are a tensile stress and a compressive stress at a surface
layer part which is bended on a material (a top surface in a direction of
a sheet thickness of a sheet). Still further, it is heretofore known that
the tensile stress functions toward an outer face side of a material
which is bended, on the contrary however, that the compressive stress
functions toward an inner face side of the material. And then it is
regarded that a crack becomes to be occurred in the material because this
tensile stress becomes to be localized at the top of the bended part.

[0014]Still further, it is able to avoid the crack if a grain in a part
where the tensile stress functions becomes to be distorted in a direction
of which a force functions. In the meantime however, in a case where it
is not able to perform the distortion of the same the crack becomes to be
started occurring from such as a crystalline grain boundary or an inside
of the grain or the like. That is to say, in order to prevent from the
occurrence of the crack a distortion is required as uniformly in a
direction for a grain to be functioned by the force.

[0015]Still further, a grain in a copper alloy which is to be bend working
does not have a shape as isometrically (which is equivalent as
isotropically) in general, but the same is distorted (oblate) as slightly
because the same is performed a working of such as a rolling or the like.
Furthermore, the distortion (oblateness) becomes to be progressed by
being performed the bend working in addition thereto.

[0026]As it is described above, it is found out that it is not able to
obtain a desired material for a copper alloy of which it is able to
withstand a stern bending workability by making use of only the
technologies (the specification of such as the crystalline grains size or
the hardness or the like) that are disclosed in each of the above
mentioned patent documents. Moreover, it is found out that in order to
obtain a material which has the strength to be further stronger (the
hardness to be higher) and has a stern bending workability it is
important to comprehend a variation of a grain size before and after
performing a bend working.

[0027]And then with having regard to such as the above described problems
or the like, a problem to be solved by the present invention is to
provide a copper alloy material which has the strength to be stronger
(the hardness to be higher), which is superior in the bending
workability, and which is to be applied as desirably to
electric/electronic components, such as a connector or a terminal
material or the like.

Means for Solving the Problem

[0028]The present inventors have performed the study regarding the copper
alloy material which is to be applied as desirably to the usage of the
electric/electronic components. And hence it is found out that the
strength (a Vickers hardness) which is to be required is between 180 and
350 of the Hv. And then it is confirmed that in accordance with this
hardness it is not able to perform a bend working as easily.

[0029]And then therefore a problem to be solved by the present invention
is to obtain a copper alloy material which is superior in the bending
workability even with having the hardness to be higher. And hence it is
found out that it is desirable to have a predetermined relation regarding
the grain size before and after performing the bend working, and then
further examination is performed. And thus it becomes able to complete
the invention.

[0030]And then in accordance with the present invention it becomes able to
obtain the aspects that will be described in detail below.

[0031](1) A copper alloy material for electric/electronic components,

wherein a average grain size of 1 to 50 μm that is designated by
((a+b)/2) in which a thickness of a grain is defined to be (a) and a
width thereof is defined to be (b) which is on a cross section that is
vertical to a rolling direction,an aspect ratio (a/b) thereof is between
0.5 and 1.0,an aspect ratio (a/b) of a grain before performing a bend
working and an aspect ratio (a'/b') of which a grain is effected by a
tensile stress after performing a bend working of 90 degrees satisfy a
following (Formula 1):

2≦(a+b)/(a'/b')≦15 (Formula 1),

andthe copper alloy material has a bending workability to be excellent.

[0032](2) The copper alloy material for electric/electronic components
according to aspect 1,

[0033]wherein a Vickers hardness (Hv) on a cross section is between 180
and 350, which is vertical to the rolling direction before performing the
bend working, and

the copper alloy material has a bending workability to be excellent.

[0034](3) The copper alloy material for electric/electronic components
according to aspect 1 or 2, comprising:

[0035]Ni and/or Co between 1.0 mass % and 4.5 mass %, respectively;

[0036]Si between 0.2 mass % and 1.2 mass %; and

a remaining portion which is formed of Cu and an unavoidable impurity.

[0037](4) The copper alloy material for electric/electronic components
according to aspect 3,

wherein the copper alloy material further comprises at least one nature
between 0.005 mass % and 1.0 mass o, which is selected from a group that
is comprised of Sn, Zn, Cr and Mg.

[0038](5) The copper alloy material for electric/electronic components
according to any of aspects 1 to 4,

wherein it becomes able to perform a solution annealed recrystallization
heat treatment with a temperature between 700° C. and 1000°
C. before performing a final rolling, andit becomes able to perform a
quick cooling with a cooling rate of faster than or equal to 100°
C. per second.

[0039]Here, the aspect ratio in the above described aspect (1) is defined
as follows. A grain of an alloy is surrounded by a grain boundary. And
then the grain is oblate (distorted) due to a working of such as a
rolling or the like. And then therefore a grain size is to be evaluated
by performing a measurement of a distance from one side of the grain
boundary to the other side of the grain boundary (refer to a method of
cutting in accordance with the JIS H 0501).

[0040]And in the meantime, in order to perform the measurement of a degree
of the oblateness that is mentioned above, it is able to perform an
evaluation of the aspect ratio by performing a measurement of a grain
size on two of lines that intersect each other with an angle of 90
degrees.

[0041]In accordance with the method of performing the measurement of a
grain which is to be made use for the present invention it becomes able
to perform an observation of a grain boundary to be easier by performing
an etching with making use of an aqueous solution of a chromic acid after
performing a mechanical polishing and then performing a mirror finish
polishing of a texture on a cross section which is vertical to a rolling
direction, that is shown in FIG. 1. And then thereafter a taking a
photograph is performed as normally by making use of a scanning electron
microscope (an SEM) with a magnification between 400 times and 2000
times. And then a distance in two directions of vertical (a) and of
parallel (b) to a rolled face, that is to say, "a thickness (a)" and "a
width (b)" for each piece of the grains. And then in this case the number
of the grains that are to be measured is approximately between 50 pieces
and 100 pieces (it may be available for the number of the grains as not
so strictly). And then an evaluated value is made use for a average grain
size by performing a calculation of ((a+b)/2).

[0042]Moreover, regarding the aspect ratio after performing the bend
working a taking of a photograph is performed by making use of the SEM
for an upper part to be bended (a cross section of an outside surface
layer part) which is effected a tensile stress, after performing the
polishing and then performing the etching for the cross section of the
bended material by making use of a method that is similar to the above
description, as one example is shown in FIG. 2. Further, "the grain which
is effected the tensile stress" in accordance with the present invention
is defined here to be a grain at a vicinity of the outside surface layer
which exists in a range from the outside surface to a depth of
approximately 50 μm. Still further, in this case there is a limitation
on the number of the grains at the vicinity of the outside surface layer.
And then therefore a distance is to be measured in two directions of
vertical (a') and of parallel (b') to a direction of a bending stress,
that is to say, "a thickness (a')" and "a width (b')" for each piece of
the grains, with the number of the grains approximately between 10 pieces
and 20 pieces (it may be available for the number as not so strictly).

[0043]And then after performing the measurement, a value of (a/b) and of
(a'/b') for each of the grain sizes is designed to be evaluated, and then
an average for each of the values is designed to be evaluated.

[0044]Still further, in accordance with the present invention a test piece
is designed to be produced by performing a cutting out into a dimensions
of ten millimeters of a width and of twenty-five millimeters of a length
(a thickness is equivalent to the thickness of each of sample sheet
materials, respectively), which is vertical to a rolling direction for
each of the sample sheet materials, that is shown in FIG. 1. And then
thereafter a (W) bending of 90 degrees (Bad-way bending) is performed for
each of these bending test piece respectively, for an axis of the bending
so as to be parallel to the above mentioned rolling direction, that is
shown in FIG. 2. And then thereafter an observation is designed to be
performed whether or not exist any crack at a bended part by making use
of an optical microscope as a visual observation with a magnification of
fifty times. Still further, an observation is designed to be performed
whether or not exist any crack at the part for the bend working by making
use of the scanning electron microscope (SEM). And hence the bending
workability is to be evaluated due to the crack which is to be observed
whether or not exist. Furthermore, in accordance with this evaluation it
is desirable in accordance with the present invention that there is not
occurred any crack at all in a case where a bend radius (R) is equal to
0.2 millimeter for a test piece, though a crack is occurred in a case
where the (R) is equal to zero millimeter for the similar test piece. And
then it is further preferable in accordance with the present invention
that there is not occurred any crack at all in the case where the (R) is
equal to zero millimeter.

EFFECTS OF THE INVENTION

[0045]In accordance with the present invention it becomes able to perform
the limitation of the grain size before performing the bend working, and
it becomes able to specify the variation of the aspect ratio of the grain
before and after performing the bend working due to the distortion of the
grain by performing the bend working. And then therefore it becomes able
to obtain a copper alloy material which has the strength to be stronger,
which is superior in the bending workability, and which is to be applied
as preferably to a part and component for the usage of the electric
apparatus and of the electronic equipment. Moreover, it becomes able to
make use of an alloy of Cu--Ni--Si system or an alloy of Cu--Co--Si
system or an alloy of Cu--Ni--Co--Si system for the alloy in accordance
with the present invention. Further, it becomes able to obtain the copper
alloy material which has the properties to be further superior to others,
by performing the further addition of Sn, Zn, Cr and Mg.

[0046]Furthermore, it becomes able to obtain the material which has the
strength to be further stronger, and it becomes able to obtain the copper
alloy material as well which has the bending workability to be superior
to others, by performing the solution annealed recrystallization heat
treatment at the predetermined temperature, and then by performing the
limitation of the cooling rate.

[0047]The above and other aspects and advantages according to the present
invention will be further clarified by the following description, with
reference to the drawings to be attached as properly therefor.

BRIEF DESCRIPTION OF THE DRAWINGS

[0048]FIG. 1 is an explanatory drawing exemplary showing a location of
cutting out a bending test piece and showing an evaluation method of a
grain size before performing a bend working.

[0049]FIG. 2 is an explanatory drawing showing a direction for a bend
working of a test piece and showing an evaluation method of a grain size
after performing the bend working.

[0050]FIG. 3 is a graph showing one example of a cooling rate by making
use of each type of the liquid coolants.

BRIEF DESCRIPTION OF THE REFERENCE SYMBOLS

[0051]1. GRAIN BEFORE PERFORMING A BEND WORKING

[0052]2. GRAIN AFTER PERFORMING THE BEND WORKING

BEST MODE FOR CARRYING OUT THE INVENTION

[0053]A desired embodiment regarding a copper alloy material in accordance
with the present invention will be described in detail below.

[0054]And regarding the copper alloy material in accordance with the
present invention a shape will not be limited at all in particular,
however, the same has a shape of such as a sheet material, a bar
material, a wire rod, a bar stock, a foil, or the like. And then it is
able to make use of the same for any type of the electric/electronic
components. Moreover, the part and component will not be limited at all
in particular, however, the same can be applied to such as a connector, a
terminal material, relay, a switch, a lead frame, or the like, and a
connector or a terminal material for such as a usage of being mounted on
to a motor vehicle or the like.

[0055]Here, the ground of the average grain size of the copper alloy
material in accordance with the present invention to be within the range
of 1 to 50 μm is because that in a case where the average grain size
is smaller than 1 μm the calculated average grain size may become to
be smaller than 1 μm in a case where only grains of which it is able
to perform the observation of the grain boundary as clearly are
extracted, and then that it becomes more difficult to perform a judgment
because there are a plurality of grains of which it is not able to
perform the observation of the grain boundary as clearly, in the meantime
however, that the bending workability becomes to be worsened in a case
where the bend working is performed for a mixed grain which contains such
a texture. And then therefore the lower limit is set up to be 1 μm.

[0056]And in the meantime, the ground of which the upper limit is set up
to be 50 μm is because that in a case where the average grain size is
larger than 50 μm an area of the grain boundary in the material
(sheet) becomes to be smaller, and that the bending workability becomes
to be deteriorated because the bending stress at the period of performing
the bend working becomes to be localized at less grain boundaries. And
then therefore it is desirable for the average grain size to be 2 to 20
μm, and then it is further preferable for the same to be 3 to 10
μm.

[0057]Moreover, in accordance with the present invention it is desirable
for the Vickers hardness (Hv) on a cross section which is vertical to the
rolling direction to be between 180 and 350. And the ground to be within
this range is because that it is heretofore known that the lower the
hardness of a material is, the further excellent the bending workability
becomes to be in general, and then that the lower limit is set up to be
limited in order to perform an improvement of the bending workability of
a material which has the hardness to be relatively harder of which the Hv
is higher than or equal to 180 in accordance with the present invention.
And in the meantime, the ground of which the upper limit of the Hv is set
up to be 350 is because that a phenomenon becomes to be occurred which is
called an embrittlement of a grain boundary in a material which has a
high hardness that is higher than or equal to this value, and hence that
there are some cases of which it is not able to obtain an advantage with
a desirable amount of degrees for performing the improvement of the
bending workability.

[0058]Further, for the copper alloy in accordance with the present
invention it may be available to make use of the other copper alloy
system if the same is a copper alloy of the precipitation hardened type,
such as the Corson alloy or the like. In the meantime however, it is
further preferable for a material to comprise the component and the
composition that will be described in detail below.

[0059]In the first instance, in a case where there is performed a multiple
addition of Ni and Co it is desirable for the same to be between 1.0 mass
% and 4.5 mass % in total, or it is further preferable for the same to be
between 2.2 mass % and 3.5 mass % in total. Moreover, it is desirable for
a mass ratio of the same as (Ni/Co) to be between 0.25 mass % and 2.5
mass %, or it is further preferable for the (Ni/Co) to be between 0.25
mass % and 1.25 mass %.

[0060]And in the meantime, in a case where Ni is added as singly it is
desirable for the same to be between 1.8 mass % and 4.5 mass %, or it is
further preferable for the same to be between 2.2 mass % and 3.8 mass %.
And in the meantime, in a case where Co is added as singly it is
desirable for the same to be between 1.0 mass % and 4.5 mass %, or it is
further preferable for the same to be between 1.2 mass % and 1.8 mass %.

[0061]Next, it is desirable for Si to be added between 0.2 mass % and 1.2
mass %, or it is preferable for the same to be between 0.3 mass % and 0.9
mass %, and then it is further preferable for the same to be between 0.4
mass % and 0.7 mass %. And in the meantime, there will not be limited at
all in particular regarding the mass ratio between the Ni and the Si or
between the Co and the Si or of ((Ni+Co)/Si), however, it is desirable
for each to be between 3.5/1 and 5.0/1 respectively.

[0062]Furthermore, it is desirable for the copper alloy in accordance with
the present invention to contain at least one nature between 0.005 mass %
and 1.0 mass % in total, which is to be selected from a group that is
comprised of Sn, Zn, Cr and Mg.

[0063]Here, Sn and Zn individually have a property of which the same is to
be solution heated into a mother phase of copper and then is to harden.
And then therefore there is a case where it is not able to obtain this
advantage in a case where the amount is less than 0.005 mass %. And in
the meantime, there is a case where the electrical conductivity becomes
to be prevented in a case where the same is more than 1 mass %. And then
therefore the range is set up to be within this amount. Moreover, Zn has
a further advantage as well by which it becomes able to perform an
improvement of a solder adhesiveness.

[0064]In the meantime however, it has not yet specified regarding the
advantage of Cr and Mg. In the first instance, there may be sometimes
detected these elements in a case where a chemical compound (precipitate)
of the Ni--Si system, of the Co--Si system and of the Ni--Co--Si system.
And then therefore the same may contribute the precipitation hardening.
However, there is not always detected from any of the precipitate.

[0065]Moreover, it is estimated that apart of any of Mg and Cr becomes to
be solution heated and then to contribute the solution heat hardening,
however, it is not sure. Further, the above mentioned intermetallic
compound becomes to perform a pinning of the grain boundaries, and then
it becomes able to obtain the advantage of which the grain becomes to be
prevented from growing. Furthermore, it is able to obtain the improvement
of the strength as well because of the advantage by which the grain size
becomes to be finer.

[0066]In the meantime however, in a case where the amount is less than
0.005 mass % there is a case where it is not able to obtain the result of
analysis nor the advantages that are individually described above. And in
the meantime, in a case where the same is more than 1 mass % there
becomes to be existed a plurality of crystallized precipitates in an
ingot. And hence there is a case where the hot workability becomes to be
prevented. And then therefore it is desirable for the same to be within
the above mentioned range.

[0067]Moreover, in a case where each of the elements is to be added as
singly it is further preferable to be between 0.05 mass % and 0.75 mass %
for a total amount in a case of performing a multiple addition.

[0068]And in addition to the above mentioned matter, there is not effected
as negatively to the electrical conductivity and to the strength even in
a case of performing an addition of Fe, Ti, Zr, B, V, P as singly with an
amount of less than or equal to 0.1 mass %, or as multiply with an amount
of less than or equal to 0.5 mass % in total.

[0069]Next, a manufacturing process which is desirable in order to obtain
the copper alloy material in accordance with the present invention is
embodied by such as the follows or the like. And then a schematic process
comprises the following steps of:

[0070]performing a processing of dissolving;

[0071]performing a processing of casting;

[0072]performing a processing of hot rolling;

[0073]performing a processing of facing;

[0074]performing a processing of cold rolling;

[0075]performing a processing of a solution annealed crystallization heat
treatment;

[0076]performing a processing of quick cooling (hereinafter, it is called
"quenching" as well);

[0077]performing a processing of an aging heat treatment; and

[0078]performing a processing of final cold rolling.

Moreover, it may be available for the aging heat treatment and the final
cold rolling to be performed in a reversed order. And then after
performing the final cold rolling a low temperature annealing is designed
to be performed as required.

[0079]Further, in order to obtain the copper alloy material for
electric/electronic components in accordance with the present invention
the solution annealed crystallization heat treatment is designed to be
performed at a temperature between 700° C. and 1000° C.
which is before performing the final cold rolling. And then the ground is
because that the objective is to perform the solution heat treatment as
sufficiently of the above mentioned elements, such as Ni or Co or the
like, and that it is necessary to perform with the temperature of higher
than or equal to 700° C. in order to perform the recrystallization
treatment, in the meantime however, that in a case where the temperature
becomes higher than 1000° C. it is not able to perform the heating
as easily from a manufacturing point of view, because the temperature
becomes close to a neighborhood of a melting point of copper, and hence
because that a problem becomes to be occurred, such as a partial fusion
of a material or a distortion of a shape or the like. And then therefore
if the temperature is between 800° C. and 950° C. as
preferred it becomes able to perform both of the solution heat treatment
and the recrystallization treatment as sufficiently, and it is the
temperature as well by which it becomes able to perform a production as
stably from the manufacturing point of view. And then by making use of
the solution annealed recrystallization heat treatment at this
temperature it becomes able to determine the grain size in the copper
alloy material.

[0080]Still further, in accordance with the present invention it is
desirable to perform the quick cooling with having the cooling rate to be
faster than or equal to 20° C. per second from this temperature of
the solution annealed recrystallization heat treatment. In the meantime
however, if it is not able to perform this quick cooling there may be an
occurrence of a precipitation of an element which is solution heated at
the above mentioned high temperature. And then such a particle (chemical
compound) which occurs the precipitation at the period of performing this
cooling is an incommensurate or a noncoherent precipitate which will not
contribute to the strength. Still further, such a particle becomes to
contribute as a site for generating a core at a time when a commensurate
or coherent precipitate is to be formed at the following aging heat
treatment. And then due to this particle the precipitation at a
corresponding part becomes to be progressed. And hence the properties
becomes to be effected as negatively. Still further, it is further
preferable for the cooling rate to be faster than or equal to 100°
C. per second, on the contrary however, in a case where the rate is too
fast there becomes to be occurred a distortion of a material due to a
phenomenon of expansion and contraction of the material. And then
therefore the rate is set up to be approximately 200° C. per
second at the fastest.

[0081]Still further, regarding this cooling rate a desirable rate for the
Ni--Si system is different from that for the Co--Si system and from that
for the Ni--Co--Si system. For example, in a case of the Ni--Si system
the desirable rate is faster than or equal to 100° C. per second,
and in the meantime, in a case of the Ni--Co--Si system the desirable
rate is faster than or equal to 120° C. per second, and in the
meantime, in a case of the Co--Si system the desirable rate is faster
than or equal to 150° C. per second, respectively.

[0082]Furthermore, this cooling rate is defined here to be an average rate
to 300° C. from the temperature for the solution annealed
recrystallization heat treatment as the high temperature. In the meantime
however, at a temperature which is lower than or equal to 300° C.
it is not able to obtain an occurrence of a variation as largely in the
texture. And then therefore the cooling rate is set up to this
temperature.

EXAMPLES

[0083]The present invention will be described in detailed below, with
being based on Examples. However, the present invention will not be
limited to any one of those.

Example 1

[0084]Here, each of the copper alloys which is made use for the
corresponding Examples (the present invention examples and the
comparative examples) in accordance with the present invention is formed
of an alloy (the present invention examples No. 1 to 30 and the
comparative examples No. 1 to 30) which contains a component that is
shown in the following Table 1 and the Table 2 respectively, and contains
a remaining portion which is formed of Cu and an unavoidable impurity,
respectively. Moreover, each of those alloys is dissolved by making use
of a high frequency melting furnace, and then thereafter each of these is
casted with a cooling rate between 10° C. per second and
30° C. per second to obtain an ingot which has a dimension of a
thickness of 30 mm and a width of 120 mm and a length of 150 mm,
respectively.

[0085]Next, each of those obtained ingots is maintained at a temperature
between 930° C. and 970° C. with an amount of time between
0.5 hour and 1 hour, and then the hot rolling is performed thereafter to
perform a production of a hot rolled sheet which has a thickness (t) that
equals to twelve millimeters then to be equal to ten millimeters by
performing a facing 1 millimeter off for each of the faces, and then
thereafter by performing a cold rolling the same is finished to have the
(t) to be equal to 0.25 mm.

[0086]Next, a solution annealed recrystallization heat treatment is
performed for the sheet material which has the (t) that equals to 0.25 mm
at a temperature between 700° C. and 1000° C. with an
amount of time between ten seconds and thirty seconds. And then
immediately thereafter a quenching is performed with a variety of the
cooling rates that are individually shown in the Tables. Moreover, an
aging heat treatment is performed at a temperature between 450° C.
and 550° C. with an amount of time between 1 hour and 4 hours. And
then thereafter a final cold rolling is performed as a finishing rolling
with a processing rate (draft) between five percent and thirty percent.
And thus the copper alloy material is produced. Further, a low
temperature annealing is performed as required at a temperature between
300° C. and 450° C. after performing the finishing rolling.
And then the characteristics is examined for each of the material
samples.

[0087]Here, various kinds of characteristic evaluations are performed for
each of these obtained copper alloy materials as a sample material, that
will be described in detail below. And then an obtained result is shown
in the Table 1 and the Table 2, respectively. Moreover, in each of the
Tables the "temperature of the solution annealed recrystallization heat
treatment" is abbreviated to be a "heat treatment temperature".

[0088]a. Hardness:

[0089]A sheet material is cut out from a sample material to have a
dimension of ten millimeters times twenty millimeters, and then the same
is filled with a resin by which it becomes able to perform a polishing in
a vertical direction to a rolling direction. And then thereafter the same
is finished to have a mirror face by performing a mechanical polishing
and then performing a wet polishing. And then thereafter a measurement is
performed by making use of a Vickers hardness tester for a cross section
which is vertical to the rolling direction with a load of 2 Newtons and
with 5 times of the number of the measurement for approximately a central
part of the cross section, and then an average value is evaluated.
Moreover, regarding the Vickers hardness tester the type HM-215 is made
use which is produced by AKASHI of Mitutoyo Corporation.

[0090]b. Bending Workability:

[0091]Each of the sample sheet materials is cut out as vertical to the
rolling direction with having a dimension of a width of ten millimeters
and a length of twenty-five millimeters (a thickness is equivalent to the
corresponding sample sheet material), and then a test piece is produced,
that is shown in FIG. 1. And then thereafter a (W) bending (Bad-way
bending) is performed with a bending angle of 90 degrees for this test
piece with an axis of the bending to be parallel to the rolling direction
to have three types of bend radius (R) to be equal to zero millimeter,
0.2 millimeter and 0.4 millimeter respectively, that is shown in FIG. 2.
And then there is examined regarding a crack whether or not exist, by
performing a visual observation with making use of an optical microscope
with a magnification of fifty times regarding a crack whether or not
exist at a bended part, and by making use of a scanning electron
microscope (an SEM) for apart to be performed the bend working. Here, the
"GOOD" indicates no crack in the Table 1 and in the Table 2 respectively,
and in the meantime, the "NO GOOD" indicates an occurrence of a crack.
Moreover, this test is performed with being based on the JBMA-T307 (1999)
in accordance with the technical standards of Copper Elongation Society
of Japan.

[0092]Further, the measurement of the grain size for the evaluation of "NO
GOOD" is designed to be performed by performing a measurement of a grain
size at a vicinity of a crack.

[0093]c. Grain Size:

[0094]Regarding a grain size (GS: μm) before performing a bend working
a cross section of a sample sheet material (the sheet before performing
the bending test which is shown in FIG. 1) which is vertical to the
rolling direction is finished to have a mirror face by the wet polishing
and then by a buff polishing. And then thereafter the polished face is
etched for several seconds with making use of a solution in which a ratio
between a chromic acid and an aqua is one by one. And then thereafter a
photograph is taken by making use of the optical microscope with the
magnification of 200 to 400 times or by making use of a secondary
electron image of the scanning electron microscope (SEM) with the
magnification of 500 to 2000 times. And then the thickness (a) and the
width (b) of the grains are measured with approximately 50 to 100 pieces
regarding the grain size on the cross section, which is pursuant to the
method of cutting in accordance with the JIS 110501. And then an average
grain size and an average aspect ratio are evaluated by making use of
each of those values, respectively. (Refer to the paragraph number
[0010].)

[0095]Moreover, regarding a crystalline grains size after performing the
bend working a test piece, that is performed the bend working which is
similar to the description in the term of the "bend workability" of the
above described (b.), is filled with a resin. And then the same is
finished to have a mirror face by performing the wet polishing and then
by performing the buff polishing that are similar to each of the above
descriptions. And then thereafter the polished face is etched for several
seconds with making use of a solution in which a ratio between a chromic
acid and an aqua is one by one. And then thereafter a photograph is taken
by making use of the optical microscope with the magnification between
200 times and 400 times or by making use of the secondary electron image
of the scanning electron microscope (SEM) with the magnification between
500 times and 2000 times. And then the thickness (a') and the width (b')
of the grains, that exist within a range of approximately 50 μm from a
surface layer at a bended upper part, are measured with the number
approximately between ten pieces and twenty pieces regarding the grain
size on the cross section, which is pursuant to the method of cutting in
accordance with the JIS H0501. And then an average aspect ratio is
evaluated by making use of each of those values, respectively. (Refer to
the paragraph number [0010].)

[0096]Further, in the case of the present invention examples No. 6, 7, 13,
14 and of the (R) is equal to zero it is not able to perform the
measurement of the (a') and of the (b') because a crack is occurred at
each of the surface layers (surface at each of the bended parts),
respectively.

[0097]d. Cooling Rate:

[0098]An adjustment of the cooling rate is performed by changing the type
of the liquid coolants and by changing the quantity of each of the liquid
coolants in a bath which is for performing the quenching, respectively.
Moreover, the liquid coolants that are prepared are the three types of an
aqua (a water temperature between 20° C. and 30° C.), a
silicone oil (a liquid temperature between 20° C. and 30°
C.) and a salt bath (a liquid temperature of 300° C., a nitrate
salt is made use). Moreover, in the case of making use of the salt bath
each of the sample materials is cooled down to a normal temperature by
making use of a water bath as a usage of the cooling from lower than or
equal to 300° C. (a secondary cooling). Here, one example of the
cooling rate with making use of each of the baths is shown in FIG. 3.
Further, this data is a result of which a measurement is performed for a
test piece (dimensions (mm): 50 times 150 times 0.2) with installing a
thermoelectric couple.

[0099]Still further, each of these examples are the case of which a
quantity of each of the liquid coolants is approximately five liters. And
then the cooling rate becomes to be faster in an order of the aqua>the
silicone oil>the salt bath. Furthermore, this curve becomes to be
gentle in the case where the quantity of each of the liquid coolants is
reduced, respectively. And in the meantime, in accordance with the
present test it is not able to obtain any improvement of the cooling rate
as remarkably even in the case where the quantity of each of the liquid
coolants is increased, respectively.

[0100]Each of the materials in accordance with the comparative examples
has the bending workability to be worsened because each thereof does not
satisfy the Formula (1) which is specified in accordance with the present
invention, in spite of which each thereof has the hardness to be as lower
with comparing to each of the present invention examples. And hence each
thereof is inferior in the strength (the hardness) and in the bending
workability, respectively. That is because it may be considered that each
of the grains will not occur a homogeneous distortion regarding a size at
the time of performing the bend working, but that only a particular grain
will occur a distortion in size, and then that a grain boundary becomes
to be destroyed.

INDUSTRIAL APPLICABILITY

[0101]The copper alloy material for electric/electronic components in
accordance with the present invention becomes to be made use as desirable
for such as a connector or a terminal material or the like for a usage of
an electric apparatus and of an electronic equipment, and also for a
connector or a terminal material for such as to be mounted on a motor
vehicle or the like, and for electric/electronic components, such as a
relay, a switch, lead frame, or the like.

[0102]And thus the present invention is described above with the
embodiment, however, the present invention will not to be limited to
every detail of the description as far as a designation in particular,
and then it should be interpreted widely without departing from the
spirit and scope of the present invention as disclosed in the attached
claims.

[0103]Furthermore, the present invention claims the priority based on
Japanese Patent Application Publication No. 2008-029778, that is patent
applied in Japan on the 8 Feb. 2008, and the entire contents of which are
expressly incorporated herein by reference as a part of the description
of the present specification.

Patent applications by Hiroshi Kaneko, Tokyo JP

Patent applications by Kiyoshige Hirose, Tokyo JP

Patent applications by Kuniteru Mihara, Tokyo JP

Patent applications in class ALL METAL OR WITH ADJACENT METALS

Patent applications in all subclasses ALL METAL OR WITH ADJACENT METALS